Constant tension servo system for dyeing jigs



CONSTANT TENSION SERVO SYSTEM FOR DYEING JIGS Filed Feb. 2, 1962 1964 R. E. KUHN ETAL' 5 Sheets-Sheet 1 225' i055??? 5. KM? J?- PAUL FEEDER/CK R055 15, 1964 R. E. KUHN ETAL CONSTANT TENSION SERVO SYSTEM FOR DYEING JIGS Filed Feb. 2, 1962 5 Sheets-Sheet 2 l l I .III I l I l I III I. H IWUH MM M Q um 1 im Mm 1 MM E E w g N F NZ W g/W MEM an r m f 04? 5 .M

Dec. 15, 1964 R. E. KUHN ETAL 3,161,371

CONSTANT TENSION SERVO SYSTEM FOR DYEING JIGS Filed Feb. 2, 1962 I 5 Sheets-Sheet 3 i f/ w Dec. 15, 1964 R. E- KUHN ETAL CONSTANT TENSION SERVO SYSTEM FOR DYEING JIGS Filed Feb. 2, 1962 5 Sheets-Sheet 4 Dec. 15, 1964 R. E. KUHN ETAL CONSTANT TENSION SERVO SYSTEM FOR DYEING JIGS Filed Feb. 2, 1962 5 Sheets-Sheet 5 United States Patent Ofiice 3,151,371 Patented Dec. 15, 1964 3,161,371 CONSTANT TENSION SERVO SYSTEM FOR DYElNG JIGS Robert E. Kuhn, Saddle River, and Paul Frederick Rose,

Wyckotf, N.J., assignors to Somatex Inc, Passaic, NJL,

a corporation of New Jersey Filed Feb. 2, 1962, Ser. No. 170,556 1 Claim. (Cl. 242-7543) This invention relates to a novel control system for automatically maintaining constant tension in fabrics passing through a dyeing jig.

In the prior art of dyeing jigs, it is well known to shuttle a length of fabric between two beam rolls in a guided path through a dyeing vat, until the desired de- 1 gree of dyeing has been achieved. In such jigs, it is usual to employ a drive motive means which can be clutched selectively into torque engagement with either roller, which then becomes the wind up roll. The undriven roll becomes the pay off beam roll and is arranged to be retarded by a control torque supplied from a manually-adjusted drag brake on the pay off side.

The variables with which the manual operator of such a drag brake has to contend include the reciprocally varying diameters of the pay off and take up rolls during the fabric transfer, and the oscillation loads imposed by the static and dynamic centrifugal unbalance forces caused by the gravitational accumulation on one side of a roll of a mass of liquid dye while a roll is standing between reversals.

As a consequence of this difficulty for the operator manually to maintain constant tension, there will result inhomogeneity in the dyeing as well as a variation in the pick count of the fabric. Conversely, the uniformity of the product will be dependent on the skill of the operator.

The present invention obviates these difficulties and provides a high degree of uniformity in the tension on the fabric in spite of the foregoing variables, by utilizing a drag brake pneumatically-controlled by a closed servo loop of the fabric in which the error signal is generated by the displacement from a predetermined pull position of a pneumatically-tensioned dancer roll whose position reflects the tension obtained in the fabric passing through the dyeing jig.

It is the principal object of the present invention to provide a reliable and automatic means to maintain constant tension in the fabric passing through a dyeing jig.

It is another object of the invention to relieve the operator of a dyeing jig from the responsibility of having to maintain constant tension in the fabric passing through this jig.

It is still another object of the invention to provide automatic means in a dyeing jig for producing uniform dyeing results.

It is a further object of the invention to provide a design of servo control for dyeing jigs which utilizes available pneumatic valve and actuator components.

It is a still further object of the invention to provide a sensitive, mechanically stable means responsive to web tension for controlling a web transport system.

For further objects and a better understanding of the present invention reference may be had to the following detailed description taken in conjunction with the accompanying drawings, in which FIGURE 1 is a perspective view of the preferred embodiment of the dyeing jig invention as seen from the manual control station side and with the dyeing vat broken away to clarify the fabric path,

FIG. 2 is a transverse view in elevation through the line 2-2 of FIG. 1, showing the dancer roll servo feed back roller with its parallel motion gear racks and pneumatic tension bias cylinders,

FIG. 3 is a partial perspective view of the subject dyeing jig as seen from the drive and pneumatic brake side and from the opposite side end viewed in FIG. 1,

FIG. 4 is a sectional view in elevation and taken on line 4-4 of FIG. 2 showing the fabric path,

FIG. 5 is an elevational view taken on line 5-5 of FIG. 2 showing the feed back proportioning valve cam actuated by the dancer roll, and

FIG. 6 is a schematic diagram of the pneumatic servo circuit of this invention associated with the operating dyeing jig parts.

Referring now to the drawings, 8 designates a fabric web which is being withdrawn from a pay off beam roll 9 and drawn onto a wind up roll 11. It is to be understood that the foregoing designations of pay off roll and wind up roll is applicable at the illustrated moment and will be reversed between rolls 9 and 11 at each reversal of the passage of the fabric 8.

A set of idler guide rollers 12, 13, 14, 16, 17 and 18, all journalled together with rolls 9 and 11, in two end frame members 19 and 21, guide the fabric 8 through a dye vat trough 22 containing a liquid dye 23.

An idler floating pneumatically-tensioned dancer roll 24 intervenes between idler rolls 14 and 16 in the fabric c rcuit. This dancer roll 24 comprises a sleeve which is freely journailed on a dancer roll shaft 26, FIG. 2. Shaft 26 has a spur gear 27 secured to it at each end. Each spur gear 27 engages a gear rack 28 secured to each of the end frame members 19 and 21 by support members 29 and 31 respectively, FIGS. 1, 2, 3 and 5. The foregoing rack and pinion constraint, 27-28, forces shaft 26 and its dancer roll 24 to move vertically, kept horizontal and always parallel to the axes of fabric rolls 9 and 11 and guide rollers 12, 13, 14, 16, 17 and 18.

Dancer roll shaft 26, FIGS. 1 and 2, is embraced at each end by a ball bearing 2% secured to a piston rod 31. This piston rod 31 and its associated piston form the linear actuator for each of two pneumatic cylinders" 32 secured to frames 19 and 21 by supports 33. When pneumatic pressure is applied to cylinders 32 through pneumatic supply line ducts 34 and micrometer adjusted flow control valve 34 which meters the flow of input air to cylinders 32 but does not restrict the back pressure flow of air to the exhaust port on regulator 86, FIG. 6, the dancer roll 24 is forced upward to increase tension in the fabric web 8. Conversely, for a given air pressure in cylinders 32, an increasing fabric tension will force dancer roll 24 downward.

The vertical position of dancer roll shaft 26 is sensed by a pressure controller 35 whose control lever 37 acts as a cam surface, FIG. 5, so that as dancer shaftzd rises along racks 28, it forces lever 37 to rotate counterclockwise about its pivot 38. The motion of lever 37 is communicated to the pressure controller 36 by means of a plunger 39. l

The pressure controller 36 is of the well known type of pneumatic control in which an impressed pressure source is modulated so that the output pressure is made to be proportional to the displacement of lever 37. This action is schematically shown in FIG. 6 in which an input pressure supplied by line 41 is movably applied through a valve block 42 at a location determined by plunger 3h acting against spring 43. An output valve block 44 having an extended port 46 receives the input pressure from line 41 when in proper registration with input block 44. Valve block 44 is positioned by the equilibrium between spring 47 and the force exerted on a piston 48 by a pneumatic cylinder 49 due to the pressure delivered to it from a duct 51.

The action of this pressure controller 36, FIG. 5, is as follows: When cam lever 37 is forced inward by the rising of dancer roll 24 it displaces valve block 42 to the left I panel 83: w

against spring 43 so as to open 41 to port 46 in block 44and an outlet duct 52. The

pressure in duct 52 therefore rises'until the communicate ing-duct 51 delivers enough pressure to the cylinder 49 to force outputblock 44 against spring 47 far enough to the left to shut off the communication between blocks 42 and 44. Thus, a pressure level in line 52, is always servoslaved to theposition of the dancer'roll 24. t

An adjustment screw 53 is provided to :adjust the equilibrium output pressure in line 52 to any'predeterv mined value when lever 37 is undisplaced by dancer roll inlet source pressure duct,

and dancerv roll .24. When the manual three-way venting valve 88 is in the on position, a direct feed through lines 52 and 94 is made which'communicates'to pressure gauge 89 and the'input of four-way'direction selector valve 84.

Whenventing valve 88 is in the ofP position, line 52 is blocked and line 94 is: vented. as shown Tbytheconventional valve symbols illustrated. I 7

- In/the position of direction" selector valve 84 shown,

the controlled input air pressure on line 94 representing the servo feed back error signal, i'sbeing' distributed by selector Valli e 84 to lead 96 and, via shuttle valve 92 and shaft 26. Valve means 44 thus automatically vents line' 52 when its pressure exceeds the pressure demanded by the position of lever 37.

' Beam roll 9 is provided with a brake 56 and a pneumatic braking cylinder 57, while beam roll 11 is provided with a brake-58 and a pneumatic braking cylinder 59, FIG. 3. Duct lines 61 and 62 control the pressure in cylinders 57 and 59 respectively. A needle valve 52" regulates the air flow to and from cylinders57 and 59 to buffer major corrections in air pressure requirements. over controlling. Pressure controller 36 is mounted, FIG.

lead 97 and through a needle or throttle-valve 52"which buffers quick changeof air pressure in brake cylinders 57 and 59 to the brake cylinder 57 which is associated with 'the'correct roll 9 to be retarded forthe running direction shown. For the reverse condition to "that shown, selector valve 84 would be in-its opposite condition in which controlled pressure from line 94 would be distributed via line 98, shuttle valve 91,-' and line 99 to brakecylinder This prevents t 5, by the adjustable'support 61'on one' of the structural members 29 so as to afiFord an adjustment of the transfer function between dancer roll, shaft 26 position and the pressure control function of lever 37 1 'The selectivedrive system for this'dyeing jig generally indicated at 62', FIG. 6, isfa conventional ditfe'rentiall drive including a reversible motor 63, FIGSQZ and 3, a

drive belt 64, a driven pulley 6 6, and a ditferential gear box 67. Conventional means, not shown, are provided for selectively engagingbeam roll 11 or beam roll 9 as the wind up roll.

Hand wheels 68 insertion of rolls of the fabric 8 into the dyeing. jig; For

I and 69,1,l?IG. 1, are provided: for retracting the outboard journals 70 and 71 from engagement with rolls 9and .11, respectively for removal and 59 on roll 11. Selector 'valve'84 automatically vents the brake, cylinder. 57 or 59 which is not'being pressurized. The input air supply pressure lead 41 to automatic 7 control .panel 83 is regulated by the 'm'anuallyset regulator 86 and after being read by pressure gauge 87 is impressed via leads 34 andthrough micrometer flow control valve 34 on the dancerroll-tension cylinders 32. The

manual control panel 73' passes air ,-from-the input line 41 through regulator 77 to gauge 78 and on-ofi valve 76 shown in the otf position therebyfventing line 101 leading to shuttle valve-92.- J i Similarly, manual. control panel 74 passes air from the input line 41- thnough regulator' 81 togauge 82 and r on-oif valve 79 shown in its off position thereby vent- 7 ing line 102 leading to shuttle' 'valve 91.

The purpose of'the two shuttle valves 91 and 92 is to seal oif those control panels which are not being used.

manual non-automatic control of the tension in fabric 8,

separate air control panels 73 and-.74 are respectively' provided to control the .respective braking cylinders 5? and.59. 1

The panel 73 is provided with athree-way,xon-oif;jmanual pneumatic valve 76 for activating panel 73, a manually adjustable-pressure controlling valve 77, .and a pressure gauge. 78.; Similarly, panel 74 is provided with.

a three-way,'on-oif manual pneumatic valve 79 for activating panel 74, a manually adjustable pressure controlling valve81, and apressure gauge 82. v 7 When either panel 73 or 74. is under command of the dyeing jig operaton manual operation of either pressure controlling valve 77 or 81determ ines the br'akingtorque of brake 56 or 58.

When the system is on automatic servo control according to the present invention, an automatic control panel 83, FIGS. ,3 and 6, is provided, and'includes a four-way selector pneumatic valve 84 for choosingcontrol of brake 56 or 58, a manually adjustable pressure regulating valve 86 and pressure gauge 87 for setting the predetermined I tension in fabric 8 imposed by cylinders 32, and a man ual three-way venting valve 88 which'is used in the trans- Thusfeach shuttle valve, 91 or 92 has two inputs 98,

i 182, or 96,. 101, and one output 97 0-1" 99 leading to control braking cylinder;.57 or 59.

Whichever shuttle input is pressurized, or has the higher pressu e, causes the other input .lead'to be gs'efaledthereby. preventing unwanted pneumaticsneztkciretifits.

For this reason, 1it-is[necessary in :order to vent the inputs 96 and. 98 :by moving valves 84 and 88 to the .olf position, opposite that shown, in order to surrender control of the system from automatic control panel 83 to manual control panels 73- and 74. Conversely, valves .76 and 79 [must belmove'd to their olf position shown thereby venting lines 101 and 102 before'shuttle valves 91 and 92 will surrender. control'back to automatic conqtvol. panel 83; I

Thefiautomatic operation according :to'the present invention is asfollows: With the valves 76, 79, .84 and 88 in the positions shown, and the minimum air pressure to for ofcontrol'betweenrpanels and 74'and the automatic Two shuttle valves 91 and 92 associated with automatic 7 control panel 83, FIG. 6, allow the shifting between man ual control panels 73 and 74 and automatic panel 83 without pneumatic sneakcircuitsior, interferences.

The pneumatic circuit of thissystem may be followed be deliveredtby the'pressure controller 36 to an empirically predetermined valve as;re'ad on gauge 89,.a1'minimum brakingdrag is efiected which will allow the dancer roll I 24 to maintainixcontrol under the} worst operating ,COl'lditions of beanijroll unbalance. Pressure regulate-r86 is now opened-until a pressure, as read on gauge 87,

and applied to tension cylinders 32 is attained which, lifts the 'dan cerjroll 24 andits fabric loop to some inter- I mediate position'ongear racks 28.

The selective motor drive system 62 is then energized to apply drive torque toroll 11. As -th'e' fabric 8 moves throughvat 22,"it' will be subjected to the uniform tenin FIG. 6. An air pressure supply source 93 is provided which connects via pneumatic lead duct 41 to panels 8 3, 73, 74 ,andto the proportional pressure controller 36. Controller 36 has the adjustment screw 53 which sets the minimum pressure delivered to control line 52 when the dancer roll shaft 26 isin its lowest position.

In the positions of the valves shown, the system is in its automativm'ode under control of automatic panel 83 ion suppliedby cylinders 32 and regulator 86. If any 7 factor such :as'rol-l diameter variation, unbalance, or fricytionjtends to vary this set atension i the dancer roll 24 will immediately reflect this change and apply a corrective braking on cylinder- '57 due to the feed back of control lex'er'37g 1 I 3 Thus, an 'increas'ingtension"will cause dancer roll 24 to descend thereby diminishing the vpressure'onabr-ake 56 while a decrease in fabric tension will cause roll 24 to rise and increase braking on roll 9.

While various changes may be made in the detailed construction, it shall be understood that such changes shall be within the spirit and scope of the present invention as defined by the appended claim.

What is claimed is:

In a dyeing jig, a supporting end frame member, fabric web beam rolls journalled between the frame members for reverse rotation, selective reversible mechanism to drive either of said rolls as wind up roll and placing torque upon the other roll and adapted for manual and automatic operation, a dye vat disposed between the end frame members beneath the beam rolls and adapted to contain liquid dye, idler guide rollers journalled between the end frame members to guide the fabric web through the dye vat, an idler floating dancer roll means intervening between the idler rolls in the fabric circuit and including a dancer roll shaft having a spur gear secured to each end thereof and a sleeve freely journalled upon the shaft, a vertically-extending gear rack mounted on each end frame member and meshing with a spur gear to keep the dancer roll means parallel to the idler guide rollers while moving vertically, a journal bearing embracing each end of the dancer roll shaft, a pneumatic cylinder device mounted on each end frame and having a piston rod to the upper end of which a journal hearing is secured and the dancer roll means, regulated pressure means for supplying air under pressure to the pneumatic cylinder devices to extend their piston rods and to force upwardly the dancer roll whereby to increase the tension in the fabric web and to sense the downward force of the fabric upon the dancer roll, a fluid pressure impressed controller adjustably mounted upon one end frame member having cam lever means engaging the floating dancer roll means to be operated thereby and, said fluid pressure impressed controller serving to modulate its output pressure in proportional response to the displacement of the cam lever and the dancer roll, a pneumatically-operable braking device associated with each of the beam rolls, means for supplying air under pressure from the regulated pressure supply means to the pneumatically-operable beam roll braking devices, said regulated pressure supply means having a manually adjustable air regulator for setting the dancing roll to modulate the drag torque of a brake and to fix the tension of the fabric to be maintained by the dancer roll.

References Cited in the file of this patent UNITED STATES PATENTS 2,557,185 Gibbs June 19, 1951 2,675,191 McGraw Apr. 13, 1954 2,922,594 Pawlowski Jan. 26, 1960 2,965,326 Rockstrom Dec. 20, 1960 2,983,463 Aaron et al. May 9, 1961 

